Exemplary embodiments of the invention relate to components of a rotary-wing aircraft susceptible to corrosion damage and, more particularly, to a method for preventing or reducing corrosion damage to such a component of a rotary-wing aircraft.
A rotary-wing aircraft includes components, such as gearboxes for example, typically constructed from aluminum and magnesium alloys. As a result of exposure of such components to the environment, these alloy materials are susceptible to both general corrosion and galvanic corrosion. For example, the presence of water or moisture on the outer surface of the component may cause corrosion and other environmental conditions, such as chemical fallout and saltwater for example, may exacerbate corrosion. Alternatively, electro-chemical incompatibility with adjacent components can lead to galvanic corrosion. Both corrosion modes cause the material of the component to deteriorate, thereby reducing the cross-section thickness thereof. In some instances, the component's effective cross-section may be excessively reduced such that the structural integrity of the component is compromised.
Conventional rotary-wing aircraft component repair methods allow for dimensional restoration of aluminum and magnesium structures using a variety of techniques including, but not limited to, epoxy bonding, plasma spray, high velocity oxygen fuel (HVOF) thermal spray and fusion welding for example. High temperature repair techniques may result in unacceptable component distortion and degrade the substrate material properties by over-aging or solutioning. Epoxy bonding can break or spall during service, allowing the environmental elements to attack the underlying material. Subsequent attacks on the material will deteriorate wall thickness such that the component is no longer usable. In addition, none of these repair methods result in the formation of a deposit suitable for carrying a load.